Open Circuit/Short To Power Check; Engine Coolant Temperature Sensor Wiring - Detroit Diesel EPA07 Series 60 DDEC VI Troubleshooting Manual

29.2 SPN 110/FMI 3
29.2.1

Open Circuit/Short to Power Check

Check as follows:
1. Turn the ignition ON (key ON, engine OFF).
2. Check for multiple codes.
[a] If codes 110/3, 174/3, 175/3 and 3510/3 are active, go to step 3.
[b] If only fault 110/3 is active, go to step 6.
3. Disconnect the Supply Fuel Temperature Sensor.
4. Measure the voltage between pin 1 of the SFT Sensor and ground.
[a] If the voltage is greater than 2.75 volts, repair the short to power between pin 55 of
the MCM 120–pin connector and the Engine Coolant Temperature Sensor, the Engine
Oil Temperature Sensor and the Supply Fuel Temperature Sensor. Refer to section
29.2.1.1.
[b] If no voltage is present on pin 1 of the SFT Sensor, repair the open between pin 55 of
the MCM 120–pin connector and the Engine Coolant Temperature Sensor, the Engine
Oil Temperature Sensor and the Supply Fuel Temperature Sensor. Refer to section
29.2.1.1.
5. Disconnect the ECT Sensor.
6. Measure the resistance across pins 1 and 2 of the ECT Sensor. See Figure 29-1.
Figure 29-1

Engine Coolant Temperature Sensor Wiring

[a] If the resistance is greater than 4 kΩ, replace the sensor. Refer to section 29.2.1.1.
[b] If the resistance is less than 4 kΩ, go to step 7.
7. Turn the ignition ON (key On, engine OFF).
8. Measure the voltage between pins 1 and 2 of the ECT Sensor harness connector.
29-4
All information subject to change without notice.
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